This invention relates to a bagging apparatus and method that is particularly adapted for use in a commercial bakery for automatically bagging a freshly baked product, such as a loaf of bread, into a plastic bag or wrapper. Commercial apparatus has been marketed for many years by AMF Bakery Products Division, Richmond, Va., for automatically inserting freshly baked loaves of bread into plastic bags or wrappers. U.S. Pat. No. 3,451,192 to J. F. Irwin, assigned to applicant's assignee, describes and claims such a machine that has been commercially used for many years. Although that machine has enjoyed considerable commercial success, its speed of operation is limited to bagging approximately 55 to 60 loaves of bread per minute. At high speeds of operation, the vibration and wear on certain parts of the machine are exceedingly high.
Briefly, the bagger of the Irwin patent operates by first inflating the plastic bag or wrapper that is tubular in shape with one end closed and one end open, then horizontally inserting top and bottom scoop shaped members into the opened bag, then raising the top scoop to hold the month of the bag open, and then returning the scoops and open bag horizontally to pull the bag over a loaf of bread that has been inserted into the path of motion of the open bag. Referring to the drawings of the Irwin patent, which is incorporated in its entirety herein by reference, the top and bottom scoops 114,115 are secured to a horizontally reciprocating shuttle or slide bearing 80 that slides on a horizontally mounted slide shaft 79. The shuttle or slide bearing is reciprocated by means of a long, oscillating lever 61 that is connected to the shuttle by means of an intermediate pivot arm 85. The long oscillating arm is pivoted at its bottom end about a fixed pivot and is driven by means of a drive mechanism that includes a gear box 35.
At the high speeds of 55 to 60 bagging operations per minute, the sliding bearing 80 on which the scoops ride is subject to abrupt stops and starts 110 to 120 times each minute of operation. This creates considerable vibration. Additionally, the long, oscillating lever 61 gains substantial momentum during its pivoting motion and its abrupt changing of directions twice each cycle of operation puts considerable strain and wear on the gear box. The noise cause by this type of operation is considerable and contributes to an unpleasant working environment.
Furthermore, the long, oscillating lever 61 and intermediate pivot arm 85 impart nonuniform velocity to the shuttle member 80 that carries the scoops, thus producing jerking movements during portions of the horizontal reciprocation of shuttle member 80, further adding to vibration, excessive wear, and noise.
A further disadvantage encountered in the Irwin bagging machine is that when adjustments were made to the height of separation of the top scoop from the bottom scoop to accommodate bags of different sizes, the top scoop became inclined or cocked. This led to difficulties in adjusting the tension that the scoops imparted to the open mouths of the plastic bags. Also, the above-mentioned nonuniform and jerking motion of the scoops in their horizontal reciprocations was undesirable in getting the scoops into the mouth of the bag and in pulling the bag over the loaf of bread.
The deficiencies discussed above have resulted in higher than desired repair and maintenance activity, limitation on speed of operation, and undesired vibration and noise during operation.
U.S. Pat. Nos. 3,618,292 and 3,930,352 both show bag scoops that pivot into an inflated bag to hold the bag open to receive bakery buns. However, those scoops are on the sides of the bun packages and the buns are pushed into the open bag by an overhead pusher on an endless belt. The scoops described in those patents move only about three inches during operation and, as mentioned, are positioned on the sides of the bag so that the buns may be pushed into the open bag. Those scoops and their operation are not suitable for a bread bagger where the scoops must be moved approximately 44 inches and where top and bottom scoops pull the bag over a stationary loaf of bread.